The present invention relates to a sheet conveying apparatus and sheet conveying method, and specifically to a conveying apparatus and conveying method of recording sheet in an image forming apparatus such as a copier, printer, facsimile, or similar apparatus.
In the sheet conveyance in an image forming apparatus such as a copier, printer or facsimile, one of problems is a static electricity problem which is generated by triboelectric charging, or charging caused by peeling while conveying the sheet. A conveyance failure such as sheet jamming, skewing, deviation of conveyance timing, or sheet misalignment in the delivery sheet section, and further, a failure such as image quality lowering are caused by static electricity.
Conventionally, in order to prevent the generation of such static electricity, a discharging brush is made to be in contact with the conveying sheet.
However, at the present, the static electricity can not be sufficiently discharged by the discharging brush, and failures as described above are not perfectly prevented, therefore, satisfactory stability and reliability are not obtained in the sheet conveying section.
As a finishing apparatus of recording sheet in the image recording apparatus, a recording sheet reversing apparatus using a drum-like recording sheet reversing means is disclosed in Japanese Patent Publication Open to Public Inspection Nos. 85662/1996 and 85663/1996. In this recording sheet reversing apparatus, the recording sheet is reversed by turning a drum after the leading edge of the recording sheet is held by the drum, and the recording sheet is reversed such that trailing edge of the recording sheet is separated from the peripheral surface of the drum after being conveyed along the peripheral surface of the drum, and thus, the sheet reversing process is completed. In such the recording sheet reversing apparatus, the charging caused by peeling occurs when the recording sheet is separated from the drum, which results in a trouble in the recording sheet conveyance, and it is difficult to fully eliminate the static electricity by discharging using the discharging brush.
That is, as described above, such the problem is specifically conspicuous in the drum-like recording sheet reversing apparatus that it is difficult to fully discharge the static electricity by the discharging brush. The above-described trouble in the recording sheet conveyance in the recording sheet reversing apparatus is an example of problems which can not be fully solved by such the conventional antistatic method using the discharging brush.